Bzoj2329: [hnoi2011] brackets fix splay

Shen Wen.

-1 indicates left parentheses, 1 indicates right parentheses, Lmax indicates the maximum continuous sum from left, rmin indicates the minimum continuous sum from right, and the answer is (Lmax + 1) /2 + (-rmin + 1)/2.

Splay can be maintained.

#include<bits/stdc++.h>#define L(t) (t)->c[0]#define R(t) (t)->c[1]#define Z(t) (L(t)->s+1)#define M (l+r>>1)using namespace std;struct node{int v,s;int sum,lmin,lmax,rmin,rmax;int same;bool flip,rev;node* c[2];node(int v,node* a,node* u):v(v),sum(v){lmin=lmax=rmin=rmax=s=same=flip=rev=0;c[0]=a,c[1]=u;}}*null=new node(0,0,0),*root;void same(int s,node* t){t->flip=t->rev=0;t->sum=t->s*(t->v=t->same=s);t->lmin=t->rmin=min(t->sum,0);t->lmax=t->rmax=max(t->sum,0);}void flip(node* t){if(t->same)return same(t->v*-1,t);t->flip^=1;t->v*=-1,t->sum*=-1;swap(t->lmin*=-1,t->lmax*=-1);swap(t->rmin*=-1,t->rmax*=-1);}void rev(node* t){if(t->same)return;t->rev^=1;swap(L(t),R(t));swap(t->lmin,t->rmin);swap(t->lmax,t->rmax);}void devolve(node* t){if(t==null)return;for(int i=0;i!=2;++i){if(t->same)same(t->v,t->c[i]);if(t->flip)flip(t->c[i]);if(t->rev)rev(t->c[i]);}t->same=t->flip=t->rev=0;}node* update(node* t){devolve(L(t));devolve(R(t));t->s=R(t)->s+Z(t);t->sum=L(t)->sum+t->v+R(t)->sum;t->lmin=min(L(t)->lmin,L(t)->sum+t->v+R(t)->lmin);t->lmax=max(L(t)->lmax,L(t)->sum+t->v+R(t)->lmax);t->rmin=min(R(t)->rmin,R(t)->sum+t->v+L(t)->rmin);t->rmax=max(R(t)->rmax,R(t)->sum+t->v+L(t)->rmax);return t;}void link(bool i,node*& t,node*& s){node* d=t->c[i];t->c[i]=s;s=update(t);t=d;}void splay(int v,node*& t=root){node* d[]={null,null};while(1){devolve(t);if(v==Z(t))break;bool i=v>Z(t);v-=i*Z(t);devolve(t->c[i]);if(v!=Z(t->c[i])&&i==v>Z(t->c[i])){v-=i*Z(t->c[i]);link(i,t,t->c[i]->c[i^1]);}link(i,t,d[i]);}for(int i=0;i!=2;++i){node* s=t->c[i^1];while(d[i]!=null)link(i,d[i],s);t->c[i^1]=s;}update(t);}node* build(char* v,int l,int r){return l>r?null:update(new node(v[M]^‘(‘?1:-1,build(v,l,M-1),build(v,M+1,r)));}node*& interval(int l,int r){splay(l);splay(r-l+2,R(root));return L(R(root));}char s[100010];int main(){int n,m,u,v;scanf("%d%d%s",&n,&m,s+1);root=build(s,0,n+1);while(m--){char t[8],a[2];scanf("%s%d%d",t,&u,&v);if(*t==‘R‘){scanf("%s",a);same(*a^‘(‘?1:-1,interval(u,v));}if(*t==‘S‘)rev(interval(u,v));if(*t==‘I‘)flip(interval(u,v));if(*t==‘Q‘){node* t=interval(u,v);printf("%d\n",(t->lmax+1)/2+(-t->rmin+1)/2);}}}

　　

Bzoj2329: [hnoi2011] brackets fix splay